Russian company ARD Technology has developed a large drone that offers the prospect of delivering cargo to wind farm turbines and oil installations.

Unlike smaller drones that rely on battery power alone the SKYF drone uses a hybrid power system that offers both considerable range and lifting capacity to bring a new level of functionality to drone operations.

The key to the effectiveness of the SKYF drone is the combination of a petrol engine with electric power. Electric power alone demands heavy batteries but by using a petrol engine to generate the lifting power, considerable weight savings and an extended range can be achieved. Electric power is then use for the control system that is used to direct the route of the drone with electric power producing the instant and sensitive response that cannot be achieved with a petrol engine.

Based on a tubular frame, the SKYF drone has two main lift propellers that are powered from the central petrol engine. Toothed belt drives transmit the power from the engine to the vertical propeller shafts so that they turn at the same speed. For control there are four small double propellers at the corners that are used to control both direction and attitude to keep the drone flying in the correct direction and in a level attitude. These small propellers are similar to those found on smaller drones and by separating the lift from the control, the advantages of both types of motor can be optimised.

According to ARDN, this combination allows a 181kg payload capacity for the drone and a range up to 350km or eight hours in the air. Whilst the extended range may be of benefit in delivering cargoes in remotes areas for survey and construction work it seems likely that in more congested areas the range will be limited to line of sight operations as is the rule for smaller drones. This means that it could provide a viable means of transferring cargoes from support vessels to wind farm turbines towers or to offshore platforms thus avoiding the need for the vessel to have contact with the structures. The SKYF also offers the possibility of delivering urgent spares to ships at sea.

In practical terms, the company claims the SKYF costs around US$150 an hour to run, which is an order of magnitude considerably less than a helicopter. It can also fold down small enough so that two drones will fit in a 20-ft cargo container for easy transport. Setup takes around 10 minutes and the overall dimensions work out at 5.2 x 2.2 metres. The operational ceiling is around 10,000ft, and its autonomous flight controller operates within a precision of around 30cm.